Multi - color 19 F CSI : Simultaneous detection of differently labeled cells in vivo

Perfluorocarbon (PFC) emulsions have been used for cell tracking studies [1, 2]; furthermore, Flögel et al. recently showed it is possible to visualize inflammation in myocardial infarction and cerebral photothrombosis (PT) mouse models using F MRI [3]. In contrast to conventional H contrast agents, F markers provide unambiguous signal in vivo due to the low natural abundance of fluorine in living organisms. A further advantage of F molecular MRI is that fluorine markers possess a unique spectral signal. Therefore, chemical shift imaging (CSI) methods can be used to distinguish between cells labeled with different fluorine markers. It was previously shown that macrophages labeled with different PFC compounds can be distinguished in vitro with a single multi-color F CSI experiment [4]. This pilot study demonstrates the feasibility of distinguishing between differently labeled cells in vivo in a PT mouse model. This is possible by using fast and specific multi-color CSI methods.